McDonnell Douglas MD-94X
Proposal for a propfan-powered airliner
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The McDonnell Douglas MD-94X was a planned propfan-powered airliner, intended to begin production in 1994. Announced in January 1986,[1] the aircraft was to seat between 160 and 180 passengers,[2] possibly using a twin-aisle configuration.[3] An all-new design that was investigated internally since at least 1984,[4] the MD-94X was developed in the mid-1980s to compete with the similar Boeing 7J7. The price of oil would have to be at least US$1.40 per gallon for McDonnell Douglas to build the plane, though.[5] Configuration was similar to the MD-80, but advanced technologies such as canard noseplanes,[6] laminar and turbulent boundary layer control, side-stick flight control (via fiber optics), and aluminum-lithium alloy construction were under consideration.[7] Airline interest in the brand-new propfan technology was weak despite claims of up to a 60% reduction in fuel use, and both aircraft were canceled.[citation needed]
| MD-94X | |
|---|---|
| A model of the proposed McDonnell Douglas MD-94X clean-sheet aircraft with two propfan engines | |
| General information | |
| Type | Airliner |
| National origin | United States |
| Manufacturer | McDonnell Douglas |
| Status | Canceled project |
| Number built | None |
| History | |
| Developed from | McDonnell Douglas MD-80 |
Under development at the same time were two propfan-powered commercial variants of the MD-80. The "MD-91X" would have seated 100-110 and entered service in 1991. The "MD-92X," a 150-seat aircraft targeted for service entry in 1992,[2] was originally to be a 76 in stretch (1.9 m) of the MD-80.[3] The price per engine would have been an estimated US$ 1.6 million dollars more for the propfans than for the MD-80's Pratt & Whitney JT8D-200 series engines.[8] Existing DC-9s and MD-80s would also have been eligible for an upgrade to the new propfan powerplants.[9] On May 19, 1987, McDonnell Douglas tested General Electric Aviation's unducted fan (UDF) engine in flight for the first time on an MD-80 demonstrator,[10] an aircraft that was restored after suffering an empennage separation in 1980 during the landing of a certification test flight for the DC-9 Super 80.[11]
A propfan-powered military variant of the MD-87 or MD-91X, called the P-9D, was also proposed as an anti-submarine warfare (ASW) aircraft. The P-9D was intended for use in the United States Navy's Long Range Air ASW-Capable Aircraft (LRAACA) program, which was to initially replace the existing fleet of 125 Lockheed P-3 Orion aircraft.[12] In October 1988, the Navy selected a derivative of the P-3 Orion (which was later renamed Lockheed P-7A) as the LRAACA aircraft over the P-9D.[13]
On October 10, 1989, McDonnell Douglas publicly announced that it was abandoning the development of propfan-powered aircraft, because of airline companies were concerned about the technology risk and cost compared to a conventionally-powered airliner.[14]
Specifications
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| Airplane | MD-91X[15] | MD-92X[15] | MD-94X | P-9D[12] |
|---|---|---|---|---|
| Derived from[9] | MD-87 | MD-88 | N/A (clean sheet) | MD-87 or MD-91X |
| Mixed-class seats | 114 | 165 | N/A | |
| Sale price[16] | US$25 million | >US$30 million | ||
| Length | 120 ft 11 in (36.86 m)[17] | 157 ft 4 in (47.96 m)[17] | 132 ft 2 in (40.3 m) | |
| Operating empty weight | 83,508 lb (37,879 kg) | 91,579 lb (41,540 kg) | ||
| MTOW | 133,000 lb (60,000 kg) | 155,000 lb (70,000 kg) | 165,000 lb (75,000 kg) | |
| Cruise speed | Mach 0.76 | 430 knots (490 mph; 800 km/h) | ||
| Range | 2,563 nmi (2,949 mi; 4,747 km) | 2,424 nmi (2,789 mi; 4,489 km) | 2,000 nmi (2,300 mi; 3,700 km) (4-hour loitering time) | |
| Takeoff field length[18] | 5,200 ft (1,600 m) | 7,000 ft (2,100 m) | ||
| Engines (×2) | General Electric GE36-C22 or PW-Allison 578 |
General Electric GE36-C25 or PW-Allison 578 |
General Electric GE36 or PW-Allison 578-D[13] | |
| Thrust per engine | 22,000 lbf (98 kN) | 25,000 lbf (110 kN) | 25,000 lbf (110 kN) | |
| Lower hold cargo volume | 773 cu ft (21.9 m3) | 1,250 cu ft (35 m3) | N/A | |
See also
Related development
Aircraft of comparable role, configuration, and era
